The present invention relates to a device and method for unloading a load-carrying body and, more particularly, to a device and method having a tilting ejector movable within the body.
Dump trucks have long been known in the art for use in carrying different types of loads. One such use is in the construction industry for carrying dirt or other material of relatively small material particle size in the dump truck bed. Such a material of small particle size has a tendency to stick to the bottom and sides of the dump truck bed, especially when wet, which prevents or hinders unloading of all of the material.
One solution has been to include plastic liners in the dump truck bed so that the material will slide from the bed as the material is dumped. However, such liners rapidly wear and some materials stick to such liners as easily as they stick to the bed surface. Examples of dump trucks are found in U.S. Pat. Nos. 1,927,653; 1,485,632; 4,145,824; 4,548,131; 3,880,072; 3,815,323; 2,179,726; 2,166,846; 3,739,715; 3,625,140; 4,467,712; 4,745,856; and German DE 2 152 881.
Additionally, U.S. Pat. No. 5,456,521, invented by the applicant of the present invention, discloses an unloading gate for a dump truck wherein the gate is mounted to one or more rails disposed on the bottom surface of the bed. The unloading gate moves from one end of the bed to the other to scrape and clean the bed after unloading or dumping of the material. The unloading gate in this patent may be utilized in conjunction with a conventional dump truck bed which lifts at its forward end closest to the tractor cab and utilizes gravity to dump the material from the dump truck bed. This patent is also limited in the amount of material that can be dumped due to the strength of the ejector mechanism implemented.
A need, therefore, exists for an improved ejector mechanism that overcomes the deficiencies of known aids used to assist in unloading of loads.
The present invention relates to an ejecting device for a truck which is mounted on side rails carried on the truck bed and eliminates the need for a conventional dump truck bed which lifts at one end and utilizes gravity to empty the contents of the truck bed.
In one embodiment, an ejecting device is disclosed for a truck having a frame carrying a truck bed. The bed has a bed surface, a pair of side walls, a first end, a second end, and a pivotally moveable tailgate on the second end. The ejecting device has a pair of elongate guide rails, one mounted along a top edge of each of the side walls. An ejector plate extends transversely between the side walls and has a lower edge adjacent the bed surface and a pair of side edges adjacent the side walls. A roller member assembly is attached to each of the side edges of the ejector plate and is slidable on the respective one of the pair of guide rails so that the ejector plate is moveable between a fully retracted position at the first end of the truck bed and a fully extended position at the second end of the truck bed adjacent the tailgate. At least one extendable cylinder is mounted on the truck and adapted to move the ejector plate between the fully retracted position and the fully extended position.
In one embodiment, the tailgate is moveable between a raised position when the ejector plate is in the fully retracted position and a lowered position when the ejector plate is in the fully extended position.
In one embodiment, the ejecting device has a tailgate which automatically moves to a raised position when the ejector plate is moved toward the fully retracted position and automatically moves to a lowered position when the ejector plate is moved towards the fully extended position.
In one embodiment, the ejecting device has an ejector plate with a scraping member adjustably secured to the lower edge.
In one embodiment, the ejecting device has an ejector plate with a lower edge adjacent the bed surface and one or more support wheels carried on the lower edge which ride along the bed surface.
In one embodiment, the guide rails each comprise an I-beam configuration in cross-section.
In one embodiment, guide rails each are integrally formed as part of one of the side walls of the bed.
In one embodiment, the ejecting device has a support bracket carried on each guide member assembly and a plurality of rollers on the support bracket, the rollers being adapted to ride along a respective one of the guide rails.
In one embodiment, the ejecting device has at least one vertical roller on each of the guide member assemblies adapted to vertically support and guide the ejector plate and at least one lateral roller adapted to laterally position and guide the ejector plate along the respective one of the guide rails.
In one embodiment, the ejecting device has one or more bearing surfaces on the guide rails adapted so that the guide member assemblies are slidable along the one or more bearing surfaces on the guide rails.
In one embodiment, the ejecting device has a support bracket carried by the frame and pivotally supporting one end of the extendable cylinder wherein the support bracket is centrally mounted relative to the frame and the extendable cylinder is centrally and pivotally attached to the ejector plate.
In one embodiment, the ejecting device has a pair of extendable cylinders, one each carried on one of the side walls below the respective one of the guide rails, one end of each of the extendable cylinders being attached to opposite sides of the ejector plate for moving the ejector plate between the retracted position and the extended position.
In one embodiment, a truck has a frame and a truck bed supported on the frame. The truck bed has a bed surface, a pair of side walls extending upward from the bed surface, a first end, a second end, and a pivotally movable tailgate on the second end. The bed has a pair of elongate guide rails, one mounted along a top edge of each of the side walls. An ejector plate extends transversely between the side walls and has a lower edge and a pair of side edges. A guide member assembly is attached to each of the side edges of the ejector plate and is slidable on the respective one of the pair of guide rails so that the ejector plate is movable between a fully retracted position at the first end of the truck bed and a fully extended position at the second end of the truck bed adjacent the tailgate. At least one extendable cylinder is mounted on the truck and adapted to move the ejector plate between the fully retracted position and the fully extended position.
In one embodiment, the truck has a scraping member adjustably secured to the lower edge of the ejector plate.
In one embodiment, the truck has an ejector plate having one or more support wheels carried on the lower edge which ride along the bed surface.
In one embodiment, the guide rails each have an I-beam configuration in cross-section.
In one embodiment, the truck has a support bracket on each guide member assembly and a plurality of rollers carried on the support bracket, the rollers adapted to ride along a respective one of the guide rails.
In one embodiment, the truck has at least one vertical roller on each guide member assembly adapted to vertically support and guide the ejector plate and at least one lateral roller adapted to laterally position and guide the ejector plate along the respective one of the guide rails.
In one embodiment, the truck has a support bracket carried by the frame and pivotally supporting one end of the extendable cylinder wherein the support bracket is centrally mounted relative to the frame and the extendable cylinder is centrally and pivotally attached to the ejector plate.
In one embodiment, the truck has a pair of extendable cylinders, one each carried on one of the side walls below the respective one of the guide rails, one end of each of the extendable cylinders attached to opposite sides of the ejector plate for moving the ejector plate between the retracted position and the extended position.
It is, therefore, an advantage of the present invention to provide an unloading or ejecting device for a truck bed which both empties the contents from the bed and moves or scrapes all of the material carried within the body during dumping.
Another advantage of the present invention is to provide a device which replaces a conventional dump truck bed that must be raised at one end to empty the contents from the bed.
Yet another advantage of the present invention is to provide a device that increases the amount of material that can be removed from a truck body.